A modelling strategy that accounts for measurement outside the laboratory, where one cannot base measurements on a single simple law, will have to drop the requirement that the model is a homomorphic mapping of the empirical relational structure. The model used for measurement will be a...

Mathematical models are instruments of investigation, epistemological equivalent to the microscope and the telescope. In comparing the epistemological difference between models and experiments, Morgan (2005) argues that experiments offer greater epistemic power than models as a means to...

A model of a decision problem frames that problem in three dimensions: sample space, target probability and information structure. Each specific model imposes a specific rational decision. As a result, different models may impose different, even contradictory, rational decisions, creating choice...

How did the meteorologist Buys Ballot and the actuary Landré deal with errors produced by measuring methods? The method of least squares is most appropriate for dealing with measurement errors produced by precise measuring instruments. But how should one proceed in meteorology where one has to...

Trygve Haavelmo's methodological manifesto "The Probability Approach in Econometrics" not only laid down the paradigm for the research pursued at the Cowles Commission, but also sets out a strategy for measurement outside the laboratory. His conceptualization of "passive observation" is still...

There is a long standing tradition that presents economic activity in terms of fluids flowing around the economy. This idea lies behind a small but influential tradition of hydraulic modelling in economics. However, there is space between using the metaphor of money (or goods) flowing between a...

Since the beginning of the nineteenth century, a large number of price index number formulae have been developed, mostly named after their inventors, such as the Paasche and Layspeyres indexes. Parallel with the invention of new index formulae, criteria were developed for distinguishing between...

This article aims to show the mathematical contexts out of which emerged Solow's 1957 article "Technical Change and the Aggregate Production Function." In particular, it seeks to provide some understanding of its most striking feature, namely, the highly aggregate level on which technical change...

For the purposes of calculation, context is irrelevant: one is expected to strip away the “contingent” details, slot bare numbers into the equations, and perform the relevant maths. Medical doctors must know this. So why, asked just such a question about the likelihood of a diagnostic test...

The Representational Theory of Measurement conceives measurement as establishing homomorphisms from empirical relational structures into numerical relation structures, called models. There are two different approaches to deal with the justification of a model: an axiomatic and an empirical...